1 . Gone are the days when big businesses were looked upon by environmentalists as enemies in the fight against global warming.

Just two weeks after U. S. President Donald Trump pulled his country out of the Paris Climate Agreement, more than 900 American firms put their _______to a “We Are Still In” open letter to the United Nations. Together, they promise to help reduce America’s carbon emissions by 26 percent by 2025, _______the Paris Climate Agreement.

_______, big businesses have been taking climate change seriously for years now. Alongside energy-efficiency measures, the strongest evidence of their _______has been the number of new wind and solar projects that they have been helping to build around the world. IT firms such as Amazon and Google have been using clean energy to power their servers (服务器). Some environmentalists now believe that big businesses could become strong _______behind the worldwide spread of renewable energy. “There used to be little action,” says Marty Spitzer of the World Wildlife Fund (WWF), “Now, I see fundamental _______being made.”

More recently, this enthusiasm for environmental protection has _______from corporate headquarters to branches and suppliers, and from developed countries to emerging markets. Take Walmart, the world’s largest retailer, for example. In March 2016, it said that it would require its own operations and those along its _______chain to reduce carbon-dioxide emissions by one billion tons by 2030. This is _______to taking 211 million passenger cars off America’s roads for a year. The announcement was ________by the WWF and other conservation organizations, which are helping Walmart’s suppliers work towards this goal. Apple, maker of the iPhone, has said that seven of its biggest global manufacturers have promised to power their Apple-related ________with renewable energy by the end of this year.

According to the WWF, in the United States alone, nearly two dozen of the biggest firms have committed themselves to becoming 100 percent renewable in the near future. Hervé Touati of the Rocky Mountain Institute, a clean-energy research firm, explains the ________behind this trend. Going green improves the companies’ public image and helps attract customers, staff and investors.

Anheuser-Busch InBev, the world’s biggest brewer (啤酒公司), has lots of young people among its many ________. Many of them take environmental issues seriously. Electricity, used ________in the brewing process, amounts to a tenth of its total costs. Last year, the company set out to increase the role of renewables in generating ________to 100 percent by 2025. “My generation often takes energy and clean air for granted,” said Tony Milikin, the firm’s chief sustainability officer. “The generation coming up now looks at it totally differently.”